Barnard v. District of Columbia was a United States Supreme Court case that dealt with the issue of taxation. The case involved a dispute between the District of Columbia and a local resident, Barnard, over the taxation of certain property. Barnard argued that the taxation of his property was unconstitutional, as it violated the Fifth Amendment's prohibition against taking private property for public use without just compensation. The Supreme Court ultimately sided with Barnard, ruling that the taxation of his property was unconstitutional. The Court held that the taxation of private property for public use without just compensation was a violation of the Fifth Amendment. The Court also held that the taxation of private property for public use was a taking of private property for public use, and thus required just compensation. The Court's ruling established the principle that the government cannot take private property for public use without just compensation.

In Barnard v. District of Columbia, the Supreme Court was asked to decide whether a law passed by Congress in 1871 that allowed for the taxation of certain real estate within Washington D.C., violated the Fifth Amendment's Takings Clause. The majority opinion held that it did not violate this clause because there was no taking without just compensation and thus no violation occurred. However, Justice Field dissented from this decision arguing that while Congress had authority to pass such laws, they must be done with due regard for constitutional limitations and restrictions on their power; specifically here he argued that since the tax imposed an immediate burden upon property owners without providing any form of compensation or benefit to them in return, it constituted a taking under the Fifth Amendment which requires payment before private property can be taken for public use. He further argued that even if Congress could impose taxes on individuals as part of its police powers (which is debatable), these taxes should still provide some sort of benefit or service back to those who are paying them - something which he felt was lacking here given how much money would have been collected through this tax but never used towards any improvement projects within D.C.. As such, Justice Field concluded his dissent by stating his belief that this law should have been struck down as unconstitutional due its violation of both federal statutes and constitutional protections afforded to citizens against government takings without just compensation